Telephone-exchange system



March 16 1926.. 1,577,059

E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed Feb. 7. 1924 4 Sheets-Sheet 1 March 16 2 1926.

- 1,577,059 E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed Feb. 7. 1924 4.Sheets-She'et 2 ii" ii :l' i Q J.. NT g-III QG IIIHI N,

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fdya/ fi. 6/00? March 16 1926. 1,577,059

' E. H. CLARK TELEPHONE EXCHANGE SYSTEM ts-Sheet 3 March 16 1926. 1,577,059

- E. H. CLARK TELEPHONE EXCHANGE SYSTEM Filed Feb. 7. 1924 4 Sheets-Sheet 4 Patented Mar. 16, 1926.

, UNITED s n-res PATENT cr tics.

EDGAR H. CLARK, or nrcnmonnnlrnnnw YORK, AssIenon To wnsrnnnnnno'rnxc COMPANY, mconronarnn, .ornnw YORK, n. Y., A conronATIon OF NEW YORK. V

TELEPHONEEXCHANGE SYSTEM;

I Application filed February To all whom it mag concern:

Be alt-known that I, EDGAR H. CLARK, a citizen of the Uni-ted States of America, residing at Richmond Hill, Long Island, the county of Queens and State of New York, have invented certain new and useful Improvements in Telephone-Exchange Systemspoif which the following is a full, clear, concise, and exact-description. i

change systems and more especially to those systemsinwhi ch automatic switches are em ployed for the purpose of establishing ta-llc' ing connections.

An object of the invention, is to prevent interference when a line is functioning both as a calling and as a called line. i

Intelephone'systems which make use of switches of the coordinate type it "has been customary to providea master controlling mechanism. in association with the line switch for the. purpose. of controlling the operation thereof in such a manner as to prevent interferingconnections being made thereby. In such systems the initiation of a call causes the master controlling mechanism to operate a pair of so-called line and trunk' vertical magnets, the completion of the connection "of the calling line with an I outgoing trunk. through the line switch 'being under complete control of the master mechanism; In such systems the seizureof a calling linefby a final connector, at any time from the moment of initiation of a call until the completion thereof through the line switch is of no effect in preventing fturth'er functioning of said line switch. 7

A. feature of the invention therefore is the means for completing a connection through a line switch, of the coordinate type, directly under control of the line relay. 7 Another feature of the invention is the means for releasing an automatic switch which has been partially operated as 'a result of the initiation of a call when the line initiating "the call is simultaneously connected to by a final selector.

'Oth'er features and advantages inherent in the invention will become apparent after] a consideration of the, detailed description andthe appended claims.

The several figures of the drawing when arvaiag ed in the'manner shown in F disclose a sufficient portion of a telephone "This invent-ion relates to telephone *ex- December '2, 1924. p

main, of vertical and horizontal operating "corresponding actu'ati'ng, magnets. ma;gI1l S"a SSOCIHJt6d WVlth vertical member's 7; 1924. serialize. 691,186. 1

system employing coordinate switches to render the object and features of the invention clean Fig. 1 shows a number of subscribers ciated controlling apparatus, {and a schematic representation of "a district selector switch. i

Fig.3 shows a sender selector switch also -ot the coordinate type, and an allotter mechanism for preselecting an idlesendcr,

In the lower right-hand corner of this tig- -ure is shown a portion of 'a subscrihers sender and a schematic outline of the reg ister'mechanism. A y

v 4t'o the'lef-t of andab'ove the broken line represents a .-group*-selector switch of Fig. 2 shows a district trunk with assothe coordinate/type; To the right of the broken line is shown :a final selector switch The line switch 100, district selector switch 200, group selector switch 450, final selector switch" 400 and sender selector switch 300,"are all of the coordinate type, such as disclosed in the patentt-o ifiN. Reynolds,No. 1,507,140,"September 2-, 1924,

and further shown and described in the patent to S. Williams, J12, No. 1,517,331,

They consist, in the members and horizontal link circuits, the operating members losing controlled by are designated as line and trunk. magnets. The operation of a line and a trunk magnet in conjunction with. a horizontal magnet causes an incoming line to be connected with an outgoing trunk by means of an idle link circuit. I V p a For the purpose of better illustrating the features of the invention let it be assumed that the subscriber at} station 1O1 initiates a call. Uponremoving the receiver from link, or to the same trunk.

mechanism functions to operate a line and a the switchhook the line relay operates and it in turn initiates the operation of a master controlling mechanism in such a manner as to prevent double connections to the same The master trunk vertical magnet, after which the horizontal magnet corresponding to an idle link is ope 'ated, thus completing connection through switch 100. From the instant the call is initiated until the time that the horizontal magnet operates, the operation of switch 100 is under control of the line re lay in such a manner that should for any 1'; he latter be released, further functioning of the line switch in extending the "ailing line is impossible. Once the horizontal magnet is operated, however, the sleeve conductor of the calling line is grounded thus. rendering the calling line busy to all linal selector switches.

In systems such as disclosed in the patent to S. B. W'illiams, J12, No. 1,517,331, Dec. 2, 1924, the line relay functions as a starting relay for the master controlling mechanism. As soon as the latter is started in operation the control of the line switch in extending the calling line and associating it with a sender selector, and sender register mechanism is rendered independent of the line relay. Should therefore the calling line be connected to by a final selector switch during the period subsequent to the operation of the line relay and prior to the operation of the horizontal magnet, the release of the line relay is of no effect in preventing further functioning of the line switch 100. Under this condition the line switch will continue to operate to connect with a sender selector, which will in turn select an idle sender, even though the calling line has been meanwhile seized by a final selector switch.

From the foregoing general description it will be apparent that in such systems once the horizontal magnet operates and locks to the grounded sleeve conductor of the outgoing trunk, association of the calling line with a sender selector and a sender inevitable. However, by placing the operation of the horizontal magnet under direct control of the line relay any release of the latter prior to the operation of the horizontal magnet will cause the complete re lease of the line switch and the prevention of further outgoing selection thereby, thus preventing interference as a result of the calling line being called.

Detailed description.

hen a calling subscriber, as the sub scriber at station 101,is desirous of conversing with another subscriber, as the subscriber at station 102, the removal of the receiver completes a circuit for operating line relay 10-1. ith the line relay operated.

a circuit is thereupon completed for group relay 105. Relays 105,106 and 107 form a controlling mechanism for all lines which terminate in vertical row of contacts 110. In a similar way there will be provided other sets of control relays for each of the other vertical rows of line contacts. The circuit for operating relay 105 may be traced from battery through its winding, lcl't armature and contact of relay 107, right inner armature and contact of relay 10-1 to ground at the left armature and contact of relay 118. The operation of relay 10;") completes a circuit from battery through the left winding of relay 106, left armature and front contact of relay 105, arn'iature and back contact of relay 106, to ground through the normal contacts of relays 112 and 113. Relay 106 at its right armature and back contact opens the locking circuit for all succeeding similar relays, thus preventing lines in other vertical groups gaining simultaneous access to the same link or to the same outgoing trunk. Relay 106 locks in a circuit traced from battery throughits right hand winding and armature and locking contact, winding of relay 1013, to ground at the armatures of relays 115a and 118. Relay 10S operates in this circuit. It will be ob served that relays 108, 111, 112, and 112:1 constitute a controlling mechanism which is common to all sets of vertical group relays. lVith relays 106 and 103 operated a circuit is completed from battery through the winding of line vertical magnet 11 1-, left middle armature and contact of relay 106, arnuiture and front; contact of relay 108 to ground at the armature of relay 1151.

Assuming trunk 120 to be busy, then relay 115 associated therewith operated and a circuit is now closed from battery through the wimling of trunk vertical magnet 116, lowermost armature and back contact of relay 131, lowermost armature and front contact of relay 115, left innermost contacts of relay 106 to ground through the armature and front contact of relay 108. l lith the line vertical magnet 11.41 and trunk vertical magnet 116 operated, the master switch starts to release under control of the slow operating relays 111. and 112. The rireuit for opcn'ating relay 112 may be traced from ground at the lmver outer armature and contact of magnet 1'16, lower inner armature and contact of magnet 11 1, to battery through the winding of relay 112. ll hen relay 112 closes its front contacts an obvious operating circuit is completed for relay 111. During the interval that relays 111 and 112 are attracting their arnuitures, a circuit is completed for the horizontaln'iagnet associated with an idle link circuit.

hen relay 106 operated, a circuit was closed from battery through the ri ht-hand .windin'mzof rela "117 ri ht armature and contact? of relay 118;. right armature-and bacln'contact of relay 119; right outer armature and. back contact; of relay. 104, left outerarinaturefland contact of relay 106, to

the grounded co-ndnctorl50. Relays 117,

7 118 and Y119 form a econtrolling;mechanism groups.

which is individual to agroup' ofhorizontal links.- Similarly. relays. 121, 122; and 123 form controlling group associated with another-"set ofilinks; Relay-117 in operatiirgopens thelockingj circuit for all succeedin ga similar relays, thus preventing, simultaneous seizure of links in different Relay 117 also locks'in acircuit traced-from battery througl'i its left windingflcft armature and locking contact, windingof'relay 109 to ground'at the arinatures of relays112and-113; Relay 109 operates in this circuit. and completes an obvious operating path for relay- 119'.

Assuming. link v 135 to be the first idle link-of the group: of links to which the calling linea-has access, a :circuit is completed from battery through the right hand winding-of magnet 126,-right inner armature and back con-tact; of .re-lay'127, right inner armature and front contact of relay 125, right armature and contact of' relay 117, right armature and front contact of relay 119,

right outer armature and front contact of relay 104, left outer armature and contact of relay 106to the grounded conductor 150.

The operation of magnet 126 completes the} connection oflli ne 101 with trunk-128 caustheir'normal contacts, the'maste-r switch is released. for usein controlling the extensioniof another calling line. Magnets 114 and 116 arenow released. lVhen magnet 116 releases the short circuit is removed from the winding of trunk relay. 13l-which operates to the grounded sleeve conductor of the trunk and transfers the starting conductor 151 to the trunk relay associated witlr tli'e'nexticlle trunk. The connection through switch 100 is maintained by the continued energization of 'magnet 126 which is locked in series with relay 127 to the grounded sleeve conductor.

the time 'ofiinitiating a callun-til the actual operation of magnet 126 the latter is under direct con-trol of' line relay 104, release of circuit-*of magnet 126;

When magnet 116 I operated "ground was extended over the sleeve conductor of the From the fore going'description it'will be seen that from trunk, through the back contact of relay 202,.conductor- 2205 to battery through the Winding of relay 301. Relay 301 functions in a similar: manner to the line-relay 104 and starts the .process of 'connecting'the callmg line with an'idlesender. The above traced operating circuit for relay 301 was broken whenrelay 202 operated, but a lockingcircuit was maintained by means of the ground at the armature of relay 203. Re

lays 321, 322 and 23 function in a manner similar to that described in connection with relays 105,- 100 and 107, causing the operation of. the corresponding vertical magnet 330. Switch 350 is'of the preselector type and is normally resting upon a 'set of terminalscorrespondi'ng'to an idle sender so'that when relay 324 operates'in series with the right hand winding or relay 323, a

circuit-v is closed from battery through the winding, ofmagnet 331, brush 360 'ttllClCOOPt-Bftllilllg contact, armature and contact of relay 335, right inner armature and. contact of relay 327 to ground atthe right innerarmature and contact of relay 324.- Relay 327 at its right outer armature andbackxcontactcompletes an obvious circuit for the slow-release relay 329 which provides'a holdingiground for relays 324 and 323; V1181! relay 323. operated it connected ground through its left outer armature and contact, therightouter armature and con I 1 tact .ofrelay301, tov battery through the left winding of horizontal group relay 325; Re-

lay 325 locksin alcircuit traced from'battery through its right-hand winding and i right armature and locking contact, winding of relay 326 to ground at the lower armature and &contact .ofrnagnet 330. Magnet 331 also closes a: temporary locking circuit for itself traceable from battery through its winding, lower innerzarlnature and contact,

winding of;relay'327-toground at the armature of relay 224. Relay 327 operates in this circuit as soon as switch 350 steps ahead and opensthe shunt aro'undsaid relay andtopens the previously described circuit Ifor maintainingzrelay 329. The switch 350 it will be noted is operated as soon as 1nagnet'331 operates in an obvious circuit.

lvliile relay329 is releasing a circuit-is completedto operate the horizontal magnet as-' Assuming link sociated with an idle link. 332 to" be idle, when relay 327 operates ground is connected through its right outer armature and front contact, right armature and zcontact of relay 326, left armature and front. contact of relay 325, left armature and front contact of relay 336, left ar1nature and back contact of relay 333, to battery through-the winding of magnet 328. which will'immediatelyopen the energizing hen relay. 329 retract-s its armature the master" controlling mechanism releases caus- .EFOI" the manner in which ringing current isapphed to: the caliled 'lme and how disconnecti onttakes p'l'aicepat the iterminationkof conversation, refierence is hadf touthe Villiams patent hereiubefore reierredeto.

What sclanneds v. v, 11. Ina telephone system, a pliura' y lines, an aititomatic switch for ext preparing said automatic switch "for opera} tion, vjmeans effective upon; thee extension;

is. innthe process-of being extendediby said means effectivewhen said line is. so seized during the interval betweenjthe initiation of a call thereon and the complete operation of said automatic switch ior'arresting further operation of the latter'in extending the said calling line.

3. In a telephone system, a line, an automatic switch for extending said line, means responsive to theinitiation ot' a call on said line for preparing said automatic switch for operation, a second automatic switch, a recording mechanism, means effective upon the complete operation of said first switch for causing the connection of said second switch and said recording mechanism with said line, means under control of said recording mechanism for maintaing said first and said second automatic switches operated, and.

means effective when said line is seized as a called line subsequent to the inltiatlon of a call'thereon and prior to the extension thereof, for rendering said first auto-' matic switch ineffective to connect with said second automatic switch and said record ing mechanism.

4. In a telephone system, a line, an auto maticswitch for extending said line, a relay individual to said line, means for partially operating said automatic switch under control of said relay, a second automatic switch, a recording mechanism, means effective when said first switch is completely I switch; completely;operated aindf'mean dti irgsaid lines, means responsive to the initiation eta calh on any; one of! sa dilinesfor a plurality of operated for rendering it independent of said relay and for coninecting s! 1 second switch and said recordti ng mechamsm to: said line,means under control of said recording .mechanismflfor maintainingsaid :Qfi. fective when; saidilane is simultaneously initiating and said line with said secondswitch and said recording mechanism-c. g i

a telephone system' a calling line. aaiautomaitic switch tor extending saidiline, means under control-of the-v calling linefor partially'operatingzsaid switch, means tor completely operating said-switch, means eh festive upon the complete operation 035 said-i switch to render the latterindependent: oi the calling line, and: means efiective when:

said line is fiunctiion-ing both as a calling andi'cailled line priorzto the: complete-operatiom of the automatic" switch: to rendersaid switch ineffective to extend-"said .as1a cal-ling line V- 7' 6i, In .atelephone system, a lline, an; airtomatic switch I for extending said line, means responsive to the initiation of a call on, said line for preparing said automatic switch for operation, means effective upon the complete operation of said switch for so maintaining the latter independent of the condition of said line, and means effective when said line is simultaneously initiating an outgoing call and terminating an incoming call prior to the complete operation of said switch for rendering'the latter dependent upon the calling line.

7.7111 combination, lines, trunks, vertical rows of contacts in whichsaid lines terminate, other vertical rows of contacts in which trunks terminate, link circuits for interconnecting said lines and trunks, a plurality of operating magnets each associated with a vertical row of contacts, a plurality of connecting magnets one for each of said link circuits, means responsive to the initiation of a call on one of said lines for preparing the operation of a plurality of said rows of contacts and operating one of said connecting magnets to extend said line, and means effective when said line is simultaneously initiating and terminating a call prior to the operation of said one of said connecting ,magnets to render the latter ineffective to extend said line;

8. In combination, a calling line, a plurality of outgoing trunks, a plurality of link circuits for interconnecting said line with an idle one of said trunks, a plurality of line magnets, a plurality of-trunk mag-' nets, a plurality of connecting magnets, means effective upon the successive oper ation of a line and a trunk magnet for preparing the operation of one of said con I terminating a call and prior by I to the complete operation: 0t said first switch, to render the latter ineffective to connect 6 arness nee-ting magnets to extend the calling line, means effective upon the operation oi said one oit said connecting magnets to maintain the same in its operated condition in-- dependently of the calling line, and means effective when the calling line is simultaneously seized by a connector switch prior to the operation of said connecting magnet to cause the simultaneous release of said switch and said connecting nragnet.

In. combination, calling lines, trunks, Vertical rows of contacts in which said lines terminate, other vertical rows oi contacts in which trunks terminate, link circuits for interconnecting said lines and trunks, a plurality of operating magnets each individual to a row of contacts, a plurality of con necting magnets each individual to a link circuit, means 'for actuating a plurality of said operating magnets, for preparing the operation of one of said connecting magnets, an automatic switch, a recording mechanism, means effective upon the operation of said one of said connecting magnets i'or causing the association of said automatic switch and said recording mechanism with a calling line, means under control of said recording mechanism for maintaining said connecting magnet operated, and means ell'ectire when said calling line is simultaneously terminating an incoming call to render said connecting magnet ineil'ective to associate said calling line with said automatic switch and said recording mechanism.

10. In a telephone system, a plurality of lines, an automatic switch for extending said lines, means responsive to the initiation of a call on one 01' said lines for preparing said switch for operation, a second automatic switch for seizing said line as a called line, and means efliective when said second switch is about to seize said line while the same is in the process of being extended by said first switch for rendering said first switch ineffective to extend said line and for allowing said line to be seized by said second switch.

In witness whereof, I hereunto subscribe my name this 5th day of February A. D.

EDGAR H. CLAR K. 

